1. Field of The Invention
The present invention relates to a lamp socket for receiving a baseless lamp and for mounting on a printed circuit board.
2. Description of the Prior Art
There have been prior lamp sockets that receive baseless lamps where the socket is adapted to sandwich a printed circuit board. The socket, when in position will receive electricity from contacts on the board to lead wires from the lamp to illuminate the same.
The prior art sockets are of plastic that have a tendency to soften when heat is applied, such as when the lamp is lit or heat is generated by the electrical contacts.
In addition, the prior art sockets are provided on the lamp receptacle portion with peripheral locking tabs so that the receptacle portion may pass upward through an opening in a printed circuit board with a base portion of the socket engaging the underside of the board. The lamp receptacle is then turned and the locking tabs engage the top of the board and the entire socket assembly is locked in place. In order to illuminate a lamp placed in the receptacle, the prior art has threaded lead wires from the lamp through the base bending the same for return on the top surface of the base. With the lead wires on the top of the base, they will be in contact with conductive strip elements of the printed circuit board to pass electricity to the lamp.
Heretofore the passages in the socket for the lead wires of the lamp have been relatively small and spaced apart as best seen in U.S. Pat. Nos. 4,193,653 and 4,289,430. As can be seen from those patents, the spacing and size of the holes required manual threading of the lead wires through the respective holes. This is time consuming and requires and pre-straightening of the wires to effect entry.
In addition, each of the aforestated patents on the top surface of the base have projections from the top where the lead wires will pass over and where the wires contact the printed circuit board. Again, as can be seen, the projections are less than the length of the lead wires on the top surface so that there is a relatively small area of contact with the wires. The remaining portion of the lead wire on the surface of the wire reach is elevated above the top surface with no support underneath.
With the structure just described, the softening of the plastic will allow a groove to be formed under the wire reach which will cause the wire on the projection to pull away from the board contact causing unwanted flickering and inoperativeness of the lamp.
In addition, it should be noted that the positioning of the grooves on the underside of the base of either of the afore identified patents is such as to make them relatively close to a peripheral edge of the base. This will assist in causing greater softening of the plastic so that the unwanted groove under the wire reach is further enlarged or depressed.
Also, with the prior art devices there are no means to truly maintain the lead wires in position as they are bent from holes to grooves to holes to the upper surface. Such lack of holding may also cause the lead wires to move which in turn may cause faulty electrical connections.